The Fischer-Tropsch (FT) process has been known and has been improved and realized in many different ways. The vast majority of the current technology development is in the production of Synthesis Gas (CO+H2) (Syn-Gas) from various hydrocarbon sources such as sugar cane sap or animal fat, etc. FT reactor design has not greatly changed. All of these design concepts incorporate some form of straight flow of Syn-Gas from the inlet of the FT reactor to the outlet of the FT products into an exhaust pipe of some sort. Several of the FT reactor designs incorporate vertical straight reactor tubes in which the Syn-Gas is caused to flow across a catalyst to produce the FT reactions, producing the desired hydrocarbon products. The horizontal FT reactor design utilizes straight reactor tubes with the catalyst fixed within the reactor tubes. A fixed bed type of reactor has the catalyst held loosely fixed while the Syn-Gas moves upward through the gaps between the catalyst. A slurry type of FT reactor utilizes straight reactor tubes in a vertical orientation, often with an upward movement of the slurry which also contains the Syn-Gas and catalyst for the FT reaction, with the slurry and catalyst being recycled through the reactor. Also, because of the need to maintain consistent Syn-Gas bubble size, most FT reactor designs, particularly the slurry type reactors need to be highly pressurized.
Because types of hydrocarbon products produced by the FT reactions are based in part of the amount of time that the Syn-Gas is exposed to the catalyst within the reactor tubes, the effective length of the reactor tubes tend to be fairly long, often 3 meters or longer, which makes the overall length of the FT reactor even longer. Both the horizontal and vertical tube FT reactor can have anywhere from one to many reactor tubes, which can also effect the outside width or diameter of the FT reactor, causing current technology FT reactors to have a minimum large size.
Broadly, current technology FT synthesis facilities tend to come in two scales. The first is desk top units designed to merely demonstrate the principal to chemical engineering students. Table top units cannot produce enough liquid hydrocarbons to be significant. The second type of FT facility varies from taking up medium sized buildings to sprawling across many acres. One of the determining factors of the size of the FT facilities are the sizes of the FT reactors. These large commercial units are very expensive and are designed for installation in a particular location.